The Design and Mathematical Modeling of a Novel Power Generation Anchor Based on Vortex Induced Vibration

A novel anchor chain system that can convert fluid dynamic energy into electrical power is presented conceptually in this paper. It consists of a bluff body attached to the anchor chain and a piezoelectric cantilever beam fixed to the bluff body. The bluff body undergoes vortex induced vibration (VIV) under the action of the incoming flow and sheds vortices periodically in its wake zone which forces the beam to bend. The transverse motion model of the bluff body was established with Sarplaya's lift decomposition model. The bending model of the piezoelectric cantilever beam was established using the bending equation of the Euler-Bernoulli beam. The two-part model was used to study the transverse motion of the device, the deflection of the piezoelectric cantilever beam and the generated power. The results show that the device is feasible. In the case of a cylindrical diameter D be 100 mm, an incoming flow velocity be 0.5 m/s, a load resistance be 200 kΩ, and a beam length be 3D, the average output power can be 7.3 μW. The model can provide guidance for designing and optimizing the anchor chain system.